I have a model # PV74WT-TBWF. This is my 2nd one. It has developed a leak between the back two sections of the exchanger. Region Oil is my oil service company and they always say that the seal between sections cannot be fixed and say I need a new unit. I look at your manual (8142711R21-7/98 and see that parts for the unit are available and there is a limited lifetime warranty. This unit is very close to 10 years old and is my second because the first Burnham furnace developed a leak in less than 2 years service and was replaced by this one. I need to know if this unit can be repaired as I am very dissatisfied with the quality of the Burnham V7 series units and do not want to buy a new Burnham if this one cannot be repaired. It appears and was described by Region Oil that the problem is merely the seal between sections. This occurred 22 days after their annual inspectionand service. Who can I contact to have this unit repaired and it seems this is a warranty claim.